Tag Archives: Snow

Northern Carrion Beetle – Thanatophilus lapponicus

This is a Northern Carrion Beetle – Thanatophilus lapponicus, one of the carrion beetles in the family Silphidae. The origin of the name Thanatophilus is from Greek thanatos (θανατος)- “death” + philos (φιλος)- “loving, liking” (Bugguide.net, 2003-2021).

Northern Carrion Beetle (Thanatophilus lapponicus)

Death is part of a biological process that can be unsettling for many of us. That said, death makes way for new life. This past February, a small fawn died on our property.

February 17, 2021

We left the body where it lay. First the eagles came, then a pair of ravens. I believe a fox visited too (tracks in the snow).

Bald Eagle 2.18.2021

Fox (?) tracks in snow

Over the course of the past 12 weeks, I’ve found some very cool bugs developing in the carcass, even now in the bits of hide and bones that remain.

Did you know?

There is actually an entire field of scientific study (Forensic Entomology) where time of death of a body can be estimated by the presence and developmental stage of certain insects involved in the decomposition process. This is called determining the Post Mortem Interval or PMI. Forensic entomologists can aid law enforcement in crime investigations by surveying for species of arthropods on a corpse, and determining stages of development and feeding behavior of the arthropods present (Barnes, 2000).

Carrion beetles in the family Silphidae fall into two subfamilies: the Nicrophorinae and Silphinae. While both feed on the remains of animals, the Nicrophorinae or Burying Beetles are associated with smaller corpses like birds, mice, voles, etc., weighing under 300g, while the Silphinae utilize larger cadavers (Watson & Carlton, 2005). This preference or niche, makes them ideal for investigations related to human death or death of larger species of wildlife (as in poaching or other crimes against animals).

Northern Carrion Beetle (Thanatophilus lapponicus)
Northern Carrion Beetle (Thanatophilus lapponicus)

From Ratcliffe, 1996.

Distribution. Thanatophilus lapponicus ranges broadly throughout Canada and Alaska, across the norther United States from coast to coast, and south to Southern California, Arizona, and New Mexico (Anderson and Peck 1985, Peck and Kaulbars 1987). It is also found in Northern Europe and Asia (Hatch 1928, Schwaller 1982).

Remarks. Thanatophilus lapponicus is readily identified because of the presence of a row of small tubercles on each of the elytra intervals (Figs. 31-32, 62); it is the only silphid in North America with this distinctive form of elytra sculpturing.

https://museum.unl.edu/file_download/inline/1bde566e-27c3-4c55-9345-59057400e350

The larval stage was described by Dorsey (1940) , and a brief synopsis was given by Anderson and Peck (1985). The larva of this species is characterized by a dark brown to black color on the dorsal surface, urogomphi that are about two times the length of the 10th abdominal segment, and antennae with a large sense cone on the second segment (as in Fig. 40).

Anderson and Peck (1985) reported that individual females lay about ten eggs in the soil surrounding a carcass. The egg stage lasts 5-6 days, the first instar about 7 days, the second instar 8-10 days, and the third instar 10-12 days. While Anderson and Peck did not observe pupae, they did note that T. lapponicus is a cold-adapted species that occurs at higher elevations in the western Mountains of North America. It is often the only silphid present in some of these areas. Thanatophilus lapponicus shows a strong preference for open areas (Anderson 1982c).

Clark (1895) observed extensive predation on fly larvae by adult beetles.

Size. 9-14mm

Time of Year Seen. March-October

References:

Anderson, R.S. and Peck, S.B. (1985) The carrion beetles of Canada and Alaska. The insects and arachnids of Canada, part 13, 1–121.

Barnes, S. 2000. Forensic entomological case study and comparison of burned and unburned Sus scrofa specimens in the biogeoclimatic zone of northwestern Montana. Graduate Student Theses, Dissertations, & Professional Papers. 4655. https://scholarworks.umt.edu/etd/4655/?utm_source=scholarworks.umt.edu/etd/4655&utm_medium=PDF&utm_campaign=PDFCoverPages

Bugguide.net. https://bugguide.net/node/view/37875

Ratcliffe, B.C. 1996. The Carrion Beetles (Coleoptera: Silphidae) of Nebraska. Bull Univ. Nebr State Mus 13:1-100 https://museum.unl.edu/file_download/inline/1bde566e-27c3-4c55-9345-59057400e350

Watson, E., & Carlton, C. 2005. Succession of Forensically Significant Carrion Beetle Larvae on Large Carcasses (Coleoptera: Silphidae). Southeastern Naturalist, 4(2), 335-346. Retrieved April 27, 2021, from http://www.jstor.org/stable/3877967

Winter Crane Fly

It snowed on San Juan Island this week.  We were forecast to have LOTS of rain yesterday, but instead we got more snow.   So much snow that this former Texas gal just had to get out and experience the magic of our wooded, winter wonderland.

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I got my coat, hat, and boots on, grabbed my iPhone and a pair of gloves, wrapped a scarf around my neck and set off to walk down our lonely country road.

Hoping to photograph some of our year-round feathered residents, I had my camera phone in hand.  It was really cold outside and yet I couldn’t use the touchscreen wearing my glove.  Off it came.  I could sacrifice cold fingers if I could get a shot of one of the woodpeckers or maybe a Varied Thrush.

Heading down the driveway, I noted the way the limbs of the cedars and firs bowed down under the weight of the snow.  Beneath them, little birds scurried, scratching about in the damp humus or flitting about on lower branches, enjoying a protected shelter from the cold.   It took only a moment to spy a  Dark-eyed Junco near the house on a leafless limb of our cherry tree and the Varied Thrush perched just above my head…perhaps waiting to see if I brought more seed out for them.

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Dark-eyed Junco (Junco hyemalis)

 

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Varied Thrush

 

A bit further down the driveway, I smiled when I saw our little carved bear.  He’s not long for this world.  The carpenter ants and the damp weather are slowly turning him into sawdust….but he rallied under his snow blanket today even though his little black nose was about all you could see.

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Snow Bear

 

Wait…isn’t this post about a Winter Crane Fly?  Well, I’m getting to that part.   I certainly wasn’t anticipating seeing any invertebrates out on a day like this.  While I’ve heard of snow fleas (not really fleas, but tiny invertebrates known as collembolans or springtails) or snow scorpionflies (Boreus spp.) found in winter in our forested area, I’ve yet to see them.   It’s really a mystery how so many of these tiny creatures survive the extreme temperatures, but that’s also what makes them so interesting.

I came across the first of about ten of these tiny, winged “cranes” before I’d made it far down the road.

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Winter “Crane”

We live in a somewhat densely forested area.  Not many houses or development to interfere with the important ecological processes going on in the natural world.  At first, it appeared to be a mosquito.  Go figure. Somehow they thrive in Alaska, Minnesota, even the Arctic…in spite of frigid temperatures!

Looking closer, I speculated it was in the family Tipulidae, a common, but harmless, mosquito-looking, awkward flying, long-legged fly!  I had to do some research to figure it out.  The Tipulids are a genus in the insect order (Diptera) and commonly called “Crane Flies.”  However, a bit of digging into the literature proved I was close to my ID of this creature, but not quite there.

What I discovered is that this is indeed a Crane Fly, but not a Tipulid.  It’s a WINTER Crane Fly in the genus Trichoceridae.  They are found flying on “warm sunny afternoons in fall, winter, and spring in the contiguous U.S., including Alaska and Canada” (Pratt 2003).  In his study, Pratt (2003) observed specimens “swarming above or on the snow in temperatures between 0℃ and 10℃.”  Maybe “warm” is subjective here!

This tiny Winter Crane Fly is very similar to the Tipulids or True Crane Flies with its long slender legs, but it differs in classification because the Winter Crane Fly has three ocelli (https://www.amentsoc.org/insects/glossary/terms/ocelli)  or simple eyes that act as light sensors and are found on top of the head.  The larvae of Trichocerid flies develop in the moist humus and decay of the forest floor and undoubtedly play some ecological role in this environment i.e. in decomposition or nutrient recycling.  At a minimum, they are a nice protein-rich winter meal supplement for the little birds I’ve seen on my walk today.

While I’m not certain of the exact species, in the article by Pratt (2003), adults of one species, Paracladura trichopera, are found flying even in winter in British Columbia, Washington, Oregon, and California.   Perhaps it will suffice to say that I was intrigued at the cold-hardiness of such a tiny creature.  And I DO like the name, Winter Crane Fly!

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Winter Crane Fly Trichocerid spp.

 

References:

1. The winter crane flies of North America north of Mexico (Diptera: Trichoceridae)
Pratt H.D. 2003. Proc. Entomol. Soc. Wash. 105: 901-914.  http://www.biodiversitylibrary.org/page/16212448